public boolean commonEnd(int[] a, int[] b) {
  if(a.length >= 1 && b.length >= 1)
  {
     if (a[0] == b[0] || a[a.length-1] == b[b.length-1])
     {
      return true;
     }
     else return false;
  }
  else
  {
    return false;
  }
}
